donsutherland1

During the natural climate cycles of the past 2,000 years, the timing of peak cold and warm periods (top 51 years) during each cycle differed globally. This time, the ongoing current warm period is starkly different. Instead, the timing of the peak warming (so far, as the warming is continuing) is astonishingly uniform. This suggests an outcome (impact of growing greenhouse gas forcing) that has largely overwhelmed "regionally specific mechanisms." A newly published paper explains: In contrast to the spatial heterogeneity of the preindustrial era, the highest probability for peak warming over the entire Common Era (Fig. 3c) is found in the late twentieth century almost everywhere (98% of global surface area), except for Antarctica, where contemporary warming has not yet been observed over the entire continent. Thus, even though the recent warming rates are not entirely homogeneous over the globe, with isolated areas showing little warming or even cooling, the climate system is now in a state of global temperature coherence that is unprecedented over the Common Era... Against this regional framing, perhaps our most striking result is the exceptional spatiotemporal coherence during the warming of the twentieth century. This result provides further evidence of the unprecedented nature of anthropogenic global warming in the context of the past 2,000 years. The above chart is from the referenced paper. The complete paper can be found at: https://www.nature.com/articles/s41586-019-1401-2.epdf

It should be noted that even if temperatures are measured in whole degrees, averaging over the entire global network over yearly periods can result in values that involve hundredths, thousandths, etc. In any case, the January-June 2019 vs. January-June 1998 average was nearly 0.3 degrees C.

Through June, 2019 is running well ahead of 1998 in terms of its global anomaly (just under 0.98°C above the baseline vs. 1998's 0.69°C above the baseline on GISS). Overall, through the first six months of the year, 2019 ranked 3rd warmest. 1998 ranked 10th warmest. https://data.giss.nasa.gov/gistemp/tabledata_v4/GLB.Ts+dSST.txt http://www.columbia.edu/~mhs119/Temperature/

I didn't say anything like that. Instead, I stated that recent changes in solar activity do not explain the ongoing observed warming. That is the point made by NASA, which I quoted. There has been a decoupling of the temperature trend (rising) from solar activity (relatively stable since the 1960s with some fluctuations).

In the wake of the historic heatwaves that rolled through Europe smashing all-time records (including setting 55% of the all-time record highs for France's 1,050 weather stations), it seems that the climate change deniers are in somewhat of a frenzy to redirect public attention from what happened and the underlying scientific basis. That scientific basis concerning the existence of climate change and its anthropogenic driver is now all but unequivocal overall, despite the existence of some residual uncertainties. Two recent examples from Social Media: Joe Bastardi: "Classic horribly biased reporting, BBC puts this out, but refuses to acknowledge that the planet is greener than ever in the satellite era. guess pictures of the greening earth won't lead to deception I dare the BBC to put that latter picture up, the reality of what is going on" Tom Nelson: "'Forward projections of solar cyclicity imply the next few decades may be marked by global cooling rather than warming, despite continuing CO2 emissions' #NIPCC" Reality is different. The denial that is underway has nothing to do with science. It is a rejection of science and the scientific method. A recent paper published in Nature Human Behavior distinguishes between scientific skepticism and the "science denialism" being advanced to mislead the public about climate change. Science denialism must not be confused with scepticism. Scepticism towards scientific propositions is a crucial element of science itself. In fact, it functions as a driving force of scientific debates and increases the quality of new propositions via mechanisms such as peer review and the replication of experimental research. The common ground of this functional scepticism is the scientific ethos that scientists use data to update their prior beliefs regardless of the outcome. However, in contrast to functional scepticism, science deniers accept evidence only if it confirms their prior beliefs--that usually contradict the scientific consensus. This dysfunctional scepticism is driven by how the denier would like things to be rather than what he has evidence for, making science denialism a motivated rejection of science. https://t.co/jysNBwsVA2 Bastardi's point ignores a key point about the "greening" that is underway: Arctic warming is leading to plant growth in a region that previously was too cold to support it. In other words, this plant growth provides confirmation of the climate change that Bastardi rejects. For more than 35 years, satellites circling the Arctic have detected a “greening” trend in Earth’s northernmost landscapes. Scientists have attributed this verdant flush to more vigorous plant growth and a longer growing season, propelled by higher temperatures that come with climate change. But recently, satellites have been picking up a decline in tundra greenness in some parts of the Arctic. Those areas appear to be “browning.” Like the salmonberry harvesters on the Kenai Peninsula, ecologists working on the ground have witnessed browning up close at field sites across the circumpolar Arctic, from Alaska to Greenland to northern Norway and Sweden. Yet the bushes bereft of berries and the tinder-dry heaths (low-growing shrubland) haven’t always been picked up by the satellites. The low-resolution sensors may have averaged out the mix of dead and living vegetation and failed to detect the browning. https://phys.org/news/2018-08-ecosystems-greener-arctic.html Nelson has cited solar activity to advance calls for global cooling to get underway. Yet, global temperatures continue to rise with little credible evidence of a decline and profound evidence of a decoupling from solar activity. http://www.columbia.edu/~mhs119/Temperature/1880-1920base.png The global temperature trend has diverged from solar irradiance. NASA observed: One of the “smoking guns” that tells us the Sun is not causing global warming comes from looking at the amount of the Sun’s energy that hits the top of the atmosphere. Since 1978, scientists have been tracking this using sensors on satellites and what they tell us is that there has been no upward trend in the amount of the Sun’s energy reaching Earth. A second smoking gun is that if the Sun were responsible for global warming, we would expect to see warming throughout all layers of the atmosphere, from the surface all the way up to the upper atmosphere (stratosphere). But what we actually see is warming at the surface and cooling in the stratosphere. This is consistent with the warming being caused by a build-up of heat-trapping gases near the surface of the Earth, and not by the Sun getting “hotter.” https://climate.nasa.gov/faq/14/is-the-sun-causing-global-warming/ It is imperative that the public be able to sort fact from fiction. The body of literature on climate change is large and growing. When it comes to the noisy movement to deny climate change, a good starting point is to ask why those who deny it have refused to put their ideas to peer review. It is easy to fire empty cannons from the sidelines. Peer review requires that one's ideas hold up to rigorous scrutiny that is a defining attribute of science. But, as noted above, science denialism is a rejection of science. Thus, the peer review channel is avoided.

In searching for forecasts for the minimum Arctic Sea Ice extent, I came across one source: https://www.arcus.org/sipn/sea-ice-outlook/2019/july The median figure from that source is 4.28 million square kilometers. The statistical mean that I posted was 3.89 million square kilometers. I will probably re-run the data when I get back from abroad around 8/20 or so. By then, it should be much clearer whether 2019 can make a run at the 2012 record. As I suspect Arctic sea ice data is not normally distributed, like others above, I believe the probabilities for extremely low minimum values are higher than what is shown statistically. I also expect this year to finish with a minimum extent below 4.00 million square kilometers.

Some great charts for changes in Greenland's surface mass balance: http://climato.be/cms/index.php?climato=the-2019-melt-season-over-greenland-as-simulated-by-marv3-9

I agree. That's part of the reason I provided a brief discussion of what could change things. I suspect that changes in ice minima may not be normally distributed.

On July 26, Arctic Sea Ice Extent was 6.385 million square kilometers (JAXA). That was below the previous minimum for the date of 6.512 million square kilometers, which was set in 2012. 2012 went on to have a record low minimum figure of 3.177 million square kilometers. At present, it appears likely that 2019 will become only the second year on record with a minimum Arctic sea ice extent figure below 4.000 million square kilometers. Ongoing climate change has been driving a long-term decline in Arctic sea ice extent, even as there have been yearly fluctuations due to internal variability. Since 2000, record low figures have occurred abruptly every few years followed by partial recovery. Since 2000, record figures below 6.000 million square kilometers were established as follows: 2002: 5.513 million square kilometers (peak prior to the next record: 5.934 million square kilometers, 2003) 2005: 5.179 million square kilometers (peak prior to the next record: 5.625 million square kilometers, 2006) 2007: 4.066 million square kilometers (peak prior to the next record: 5.054 million square kilometers, 2009) 2012: 3.177 million square kilometers (peak since then: 4.884 million square kilometers, 2014) Potential Minimum Extent Scenarios: Smallest decline from 7/25 to the minimum (2000-18): 4.810 million square kilometers Smallest decline from 7/25 to the minimum (2010-18): 4.323 million square kilometers Mean decline from 7/25 to the minimum (2010-18): 3.886 million square kilometers Median decline from 7/25 to the minimum (2010-18): 3.966 million square kilometers Maximum decline from 7/25 to the minimum (2010-18): 3.069 million square kilometers Statistical Minimum Extent Scenarios (2010-18 Data): 5.000 million square kilometers or below: 99.9% 4.500 million square kilometers or below: 95% 4.000 million square kilometers or below: 62% 3.750 million square kilometers or below: 36% 3.500 million square kilometers or below: 15% 3.000 million square kilometers or below: 1% New Record Low Minimum: 3% What could change things: These are statistical measures. Greater warmth and/or a more unfavorable pattern for preserving ice could lead to larger declines than implied statistically. A sustained period of cooler weather and/or a more favorable pattern for preserving ice could lead to higher figures than implied statistically. At least through the remainder of July, the balance of risks favors a greater decline than implied statistically. In part, the historic heat in Europe that is forecast to move into Iceland and Greenland in coming days may be partially the result of the warming Arctic via Arctic Amplification and the slowing of the Atlantic Meridional Overturning Circulation (AMOC), as well as induced changes to the jet stream that lead to greater pattern persistence.

On July 9, 2019, Arctic sea ice extent fell below 8 million square kilometers (JAXA) to 7,953,297 square kilometers. That is the earliest date on record for less than 8 million square kilometers of ice. The previous earliest such date was July 10. That record was set in 2011 and tied in 2012.

That's correct.

And if there's no more snow this winter (extremely unlikely), Winter 2018-19 would be Richmond's 59th snowiest on record.

Richmond picked up 11.5" snow. All of last winter saw 12.4" snow fall at Richmond. Since 2000-2001, only 6 winters have had more snowfall than winter 2018-19. Overall, winter 2018-19 now ranks as Richmond's 59th snowiest. Since snowfall measurements were commenced, 8/21 (7%) of winters saw 30" or more snow. However, 2/7 (29%) of winters that had 10" or more snow through December wound up with 30" or more snow. 4/7 (57%) picked up 20" or more vs. 26/121 (21%) overall. In short, Richmond may be on track for a very snowy winter.

It was a fantastic storm; the 2nd biggest December snowstorm on record.

With 1.01" precipitation through 6:40 pm, Richmond's total storm total snowfall is likely between 11.0" and 12.0" assuming similar ratios to what had been achieved through 5 pm. With the 9.0" as of 5 pm, winter 2018-19 is already Richmond's 71st snowiest on record (if it does not snow again). With 11.0", winter 2018-19 would rank as Richmond's 61st snowiest on record.

It was an exciting storm and it was great to see RIC get into the heavy snow.

Most of the guidance had far lower amounts for Richmond. Occasionally, a storm will bring its heavy snowfall 25-50 miles farther north than modeled. That can make the difference between a few inches or a significant snowfall.

Today's storm was a milestone event for Richmond. Through 6 pm, Richmond had received 0.90" precipitation. That brought 2018's total precipitation to 61.33", which surpassed the 61.31" that fell in 1975 to become Richmond's 3rd wettest year on record. In addition, Richmond had received 9.0" snow through 5 pm. That smashed the daily record of 1.8", which was set in 1988. That snowfall also ranks as both the 2nd highest daily snowfall up to December 15 and the 2nd biggest snowstorm up to December 15. With additional snow having fallen since then, Richmond could be in line to have both its highest daily snowfall and biggest total snowfall up to December 15. The records up to December 15 are: Daily record: 9.4", December 12, 1917 Biggest snowstorm: 9.9", December 12-13, 1917 Finally, this snowstorm has the potential to become the 2nd largest daily snowfall and 2nd biggest snowfall for December. Those records are 15.0" from December 22, 1908 and 17.2" from December 22-23, 1908.

Here it is:

The guidance for the most part has been remarkably consistent. I didn’t run numbers for Roanoke earlier, so I don’t know whether much would have changed had I made an estimate for there yesterday.

At 3:30 pm, light snow was falling at Asheville. Light rain was also being reported at Wilmington, NC where 2018's annual precipitation record was extended to 95.96". Meanwhile, heavy rain had moved into Pensacola. Overall, the major storm that had been the focus of the computer guidance for more than a week is getting underway. Parts of North Carolina and extreme southwestern Virginia will likely pick up a significant early-season snowfall, even when sleet, freezing rain, and even rain are considered. My final snowfall estimates for select cities are below:

As of 9:30 am, Atlanta had picked up 0.22" rain. That brings 2018's total precipitation to 60.08". 2018 is only the 18th year on record that Atlanta has had 60" or more precipitation. 2018 now ranks as Atlanta's 17th wettest year on record, just ahead of 1994 when 60.02" precipitation was recorded.

So far, from a quick look at the overnight guidance and the advance of the precipitation, everything seems remarkably on track for the storm.

The numbers I posted are below:

For a hint of what may lie ahead in terms of incredible moisture, as of 9 pm CST, here are a few precipitation totals in Texas: Houston: 2.55" (heavy rain was still falling) Huntsville: 3.79" (heavy rain was still falling) Palacios: 3.42"